Safe Withdrawal Rate Calculator

The Purpose (Why?)

To simulate and compare advanced withdrawal strategies like Variable Withdrawal Strategies (VWS) against rigid Fixed Withdrawal strategies. It allows testing of "guardrails" (caps and floors) to see how they stabilize income and preserve capital. (Note: Simulations use inflation-adjusted "Real Dollars")

How it Works

Configure the Initial Balance and Base SWR. Then tune the strategy parameters: "SWR Adjustment Factor" (0 for Fixed, near 0 for % of Portfolio, ~50 for Variable), Change Caps (limits on income fluctuation), and Withdrawal Floor.

Case Studies

See how this calculator was used in these foundational lessons:

Input Specifications

PARAMETER DETAILS
Initial Balance ($)
Starting portfolio value.
EXAMPLE: $1,000,000
Safe Withdrawal Rate (percentage)
Base Safe Withdrawal Rate percentage.
EXAMPLE: 5.0%
SWR Adjustment Factor (%)
Adjustment factor:
  • 0 for Fixed Withdrawal
  • ~0 for % of Portfolio (I.E. 0.001, as adjusting by near zero is about a constant percentage of portfolio)
  • > 0 for Variable Withdrawal Strategy (VWS - 50 means the withdrawal amount changes by 50% of change in portfolio return. I.E. if portfolio returns 10%, withdrawal amount increases by 5%)
EXAMPLE: 50 (for VWS)
Max Annual Increase (%)
Maximum annual increase in withdrawal amount (VWS only).
EXAMPLE: 5.0%
Max Annual Decrease (%)
Maximum annual decrease in withdrawal amount (VWS only).
EXAMPLE: 2.5%
Withdrawal Floor (%)
Minimum withdrawal amount as percentage of initial withdrawal (VWS only).
EXAMPLE: 90.0%
Retirement Duration (Years)
Length of the retirement simulation.
EXAMPLE: 30
Real Return (%)
Expected average annual real return.
EXAMPLE: 5.8%
Standard Deviation (%)
Annual return standard deviation.
EXAMPLE: 6.1%
Annual Expense (%)
Fixed annual management or portfolio expense.
EXAMPLE: 0.0%
Visualization Example
Example Visualization